What is clonus of the foot?

Clonus is a type of neurological condition that creates involuntary muscle contractions. This results in uncontrollable, rhythmic, shaking movements.

What causes foot clonus?

Clonus is involuntary and rhythmic muscle contractions caused by a permanent lesion in descending motor neurons. Clonus may be found at the ankle, patella, triceps surae, wrist, jaw, biceps brachii.

What is a clonus reflex?

Clonus is a rhythmic oscillating stretch reflex that is related to upper motor neuron lesions. Therefore, clonus is generally accompanied by hyperreflexia. Testing for clonus is performed as part of the neurological exam.

What is clonus in the ankle?

Clonus is a series of involuntary, rhythmic, muscular contractions, and relaxations. It may be caused by interruption of upper motor neuron fibers such as stroke, multiple sclerosis or by metabolic alterations such as severe hepatic failure or serotonin syndrome 1.

What is the difference between clonus and spasticity?

Spasticity and clonus result from an upper motor neuron lesion that disinhibits the tendon stretch reflex; however, they are differentiated in the fact that spasticity results in a velocity dependent tightness of muscle whereas clonus results in uncontrollable jerks of the muscle.

What does clonus test for?

Clonus of the ankle results in repeated dorsiflexion of the ankle in response to brisk dorsiflexion of the foot. The test helps in differentiating between the involvement of the central nervous and peripheral nervous system.

Is ankle clonus ever normal?

Diagnosis. Clonus at the ankle is tested by rapidly flexing the foot into dorsiflexion (upward), inducing a stretch to the gastrocnemius muscle. Subsequent beating of the foot will result, however only a sustained clonus (5 beats or more) is considered abnormal.

How do you stop clonus?

Other than medication, treatments that may help reduce clonus include:

1. Physical therapy. Working with a physical therapist to stretch or exercise the muscles may help increase the range of motion in the damaged area.
2. Botox injections. Some people with clonus respond well to Botox injections.
3. Surgery.
4. Home remedies.

Can you improve clonus?

Physical therapy for clonus management will primarily consist of stretching, range of motion, and strengthening exercises. Stretching helps lengthen tight muscles and repetitive exposure to movement may help reduce reflex excitability. Weight bearing exercises may also be used during physical therapy treatments.

How can you tell if you have clonus in your foot?

The doctor performs a rapid dorsiflexion of the foot where the foot is held at slight tension with the toes pointed towards you. When the foot is released that will cause a clonus reaction. If there is no reaction when the foot is returned back to normal, the clonus is not present. If the foot jerks over five times, that reveals clonus.

Where does clonus occur in the human body?

Clonus may be found at the ankle, patella, triceps surae, wrist, jaw, biceps brachii. In general, clonus may occur in any muscle with a frequency of 5-8 Hz and the average period of oscillations of the ankle clonus is approximately 160-200 ms.

How long is the clonus of the ankle test?

Frequency of clonus: 5-8 Hz and the average period of oscillations of the ankle clonus is approximately 160–200 ms with plantar flexion comprising 45% of the period and dorsiflexion 55% of the period. Literature suggests that the duration of the dorsiflexion around 88.63±10.83 ms, and the duration of the plantarflexion 71.75±6.73 ms.

How often do you have to jerk your foot to find clonus?

If there is no reaction when the foot is returned back to normal, the clonus is not present. If the foot jerks over five times, that reveals clonus. The same procedure is conducted on the wrist as well, if your doctor chooses to perform a wrist clonus test. Treatment options for clonus